Slide 1

2Units & Notation

UsedforConvenience

MinimumNecessaryBasic Standard International (SI) UnitsLengthmeter (m)Masskilogram (kg)Timesecond (s)CurrentAmpere (A)TemperatureKelvin (K)Amountmole (mol)Luminouscandella (cd) Intensity

Demos: 1A10.30 Standards of Length; 1A10.65 Mole samples2

non-SI conversionsexample: density = mass/unit volumeAluminum has a density r = 270 grams per centimeter3 r = m/Vnon-SI non-SI 270 gcm3( )( )kg103 g( )102 cmm3SI SI =2.7 x 105 kg/m3

BC

usesnon-metric units=ClickerWhich map (A, B or C) shows in red the countries that do NOT use metric units?

A

Ausesnon-metricunits

drive on right

no paid maternity leave

LiberiaMyanmar

Numerical Prefixes109GigaG106MegaM103kilok10-2centic10-3millim10-6micro10-9nanon10-12picop

What are:0.01 pede2x103 mockingbirds0.001 tiacentipedeTwo kilo mockingbirdsmillitiaTo kill a mockingbird

Scientific Notation

Numbers 1

Numbers < 1

Dimensional AnalysisA submarine dives at 36 fathoms per minute. What is this in SI units?2.What is a furlong per fortnight in miles per hour?36 fathomsmin( )=1.1 m/s6 ft.fathom( )12 in.ft.( )2.5 cmin.( )10-2 mcm( )min60 s( )furlongfortnight( )0.125 milesfurlong( ) fortnight2 weeks( )week7 days( )day24 hours( )=3.7 10-4 miles/hour